Galectin-7 modulates the length of the primary cilia and wound repair in polarized kidney epithelial cells

Am J Physiol Renal Physiol. 2011 Sep;301(3):F622-33. doi: 10.1152/ajprenal.00134.2011. Epub 2011 Jun 15.


Galectins (Gal) are β-galactoside-binding proteins that function in epithelial development and homeostasis. An overlapping role for Gal-3 and Gal-7 in wound repair was reported in stratified epithelia. Although Gal-7 was thought absent in simple epithelia, it was reported in a proteomic analysis of cilia isolated from cultured human airway, and we recently identified Gal-7 transcripts in Madin-Darby canine kidney (MDCK) cells (Poland PA, Rondanino C, Kinlough CL, Heimburg-Molinaro J, Arthur CM, Stowell SR, Smith DF, Hughey RP. J Biol Chem 286: 6780-6790, 2011). We now report that Gal-7 is localized exclusively on the primary cilium of MDCK, LLC-PK(1) (pig kidney), and mpkCCD(c14) (mouse kidney) cells as well as on cilia in the rat renal proximal tubule. Gal-7 is also present on most cilia of multiciliated cells in human airway epithelia primary cultures. Interestingly, exogenous glutathione S-transferase (GST)-Gal-7 bound the MDCK apical plasma membrane as well as the cilium, while the lectin Ulex europeaus agglutinin, with glycan preferences similar to Gal-7, bound the basolateral plasma membrane as well as the cilium. In pull-down assays, β1-integrin isolated from either the basolateral or apical/cilia membranes of MDCK cells was similarly bound by GST-Gal-7. Selective localization of Gal-7 to cilia despite the presence of binding sites on all cell surfaces suggests that intracellular Gal-7 is specifically delivered to cilia rather than simply binding to surface glycoconjugates after generalized secretion. Moreover, depletion of Gal-7 using tetracycline-induced short-hairpin RNA in mpkCCD(c14) cells significantly reduced cilia length and slowed wound healing in a scratch assay. We conclude that Gal-7 is selectively targeted to cilia and plays a key role in surface stabilization of glycoconjugates responsible for integrating cilia function with epithelial repair.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Membrane / physiology
  • Cells, Cultured
  • Cilia / physiology*
  • Cilia / ultrastructure*
  • Dogs
  • Epithelial Cells / cytology
  • Epithelial Cells / physiology*
  • Epithelial Cells / ultrastructure
  • Galectins / genetics
  • Galectins / physiology*
  • Humans
  • Integrin beta1 / physiology
  • Kidney / cytology
  • Kidney / physiology*
  • Kidney / ultrastructure
  • Kidney Tubules, Proximal / cytology
  • Kidney Tubules, Proximal / physiology
  • Kidney Tubules, Proximal / ultrastructure
  • Mice
  • Mice, Knockout
  • Protein Binding / physiology
  • Rats
  • Swine
  • Wound Healing / physiology*


  • Galectins
  • Integrin beta1
  • LGALS7 protein, human
  • Lgals7 protein, mouse